smog ??

[1637]

my 82 350 did not pass smog test,they said it was getting vac to the egr valve at idle .and opening it to early,anyone know were that vac is coming from??i just put a new vac canister,and yes i do live in calif

 

[imiceman44]

my 82 350 did not pass smog test,they said it was getting vac to the egr valve at idle .and opening it to early,anyone know were that vac is coming from??i just put a new vac canister,and yes i do live in calif

Wild guess here, the vacuum is coming from the carb and you might have the wrong port feeding the EGR.
I would check a vacuum diagram and compare it.
I will also ask my smog guy if he has any thoughts.

 

[throttleissues]

Yeah, I seem to remember EGR getting vacuum from a ported source rather than manifold vacuum. That way it has more vaccum at cruise than idle. Port should be higher on carb, not in the baseplate.

 

[imiceman44]

Yeah, I seem to remember EGR getting vacuum from a ported source rather than manifold vacuum. That way it has more vaccum at cruise than idle. Port should be higher on carb, not in the baseplate.

Actually at Idle I belive it has slim to no vacuum.
That is how I knew I had a wrong port.

 

[1637]

1637

from the temp switch one line go to the canister,one goes to the egr and two go to the body of the carb ,could something be wrong in my carb?

 

[throttleissues]

Actually at Idle I belive it has slim to no vacuum.
That is how I knew I had a wrong port.

Exactly what I was meaning, sorry if it didn't sound that way. Ported vacuum is almost nothing at idle and high during part-throttle.

 

[AZ79K5Project]

Here's a pic from my 79:
View attachment 65792

I don't know about your emission control stuff - here's a pic of a 79.

 

[1637]

1637

thanks for the help i did have two of the vac going to the carb switched.thanks again happy new year

 

[kevin400ex]

it needs to be coming from a part throttle vacuum source and thru a thermal switch as well.